US20020098936A1 - Toroidal transmission with a starting clutch - Google Patents
Toroidal transmission with a starting clutch Download PDFInfo
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- US20020098936A1 US20020098936A1 US09/764,233 US76423301A US2002098936A1 US 20020098936 A1 US20020098936 A1 US 20020098936A1 US 76423301 A US76423301 A US 76423301A US 2002098936 A1 US2002098936 A1 US 2002098936A1
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- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F16—ENGINEERING ELEMENTS AND UNITS; GENERAL MEASURES FOR PRODUCING AND MAINTAINING EFFECTIVE FUNCTIONING OF MACHINES OR INSTALLATIONS; THERMAL INSULATION IN GENERAL
- F16H—GEARING
- F16H37/00—Combinations of mechanical gearings, not provided for in groups F16H1/00 - F16H35/00
- F16H37/02—Combinations of mechanical gearings, not provided for in groups F16H1/00 - F16H35/00 comprising essentially only toothed or friction gearings
- F16H37/06—Combinations of mechanical gearings, not provided for in groups F16H1/00 - F16H35/00 comprising essentially only toothed or friction gearings with a plurality of driving or driven shafts; with arrangements for dividing torque between two or more intermediate shafts
- F16H37/08—Combinations of mechanical gearings, not provided for in groups F16H1/00 - F16H35/00 comprising essentially only toothed or friction gearings with a plurality of driving or driven shafts; with arrangements for dividing torque between two or more intermediate shafts with differential gearing
- F16H37/0833—Combinations of mechanical gearings, not provided for in groups F16H1/00 - F16H35/00 comprising essentially only toothed or friction gearings with a plurality of driving or driven shafts; with arrangements for dividing torque between two or more intermediate shafts with differential gearing with arrangements for dividing torque between two or more intermediate shafts, i.e. with two or more internal power paths
- F16H37/084—Combinations of mechanical gearings, not provided for in groups F16H1/00 - F16H35/00 comprising essentially only toothed or friction gearings with a plurality of driving or driven shafts; with arrangements for dividing torque between two or more intermediate shafts with differential gearing with arrangements for dividing torque between two or more intermediate shafts, i.e. with two or more internal power paths at least one power path being a continuously variable transmission, i.e. CVT
- F16H37/086—CVT using two coaxial friction members cooperating with at least one intermediate friction member
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- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F16—ENGINEERING ELEMENTS AND UNITS; GENERAL MEASURES FOR PRODUCING AND MAINTAINING EFFECTIVE FUNCTIONING OF MACHINES OR INSTALLATIONS; THERMAL INSULATION IN GENERAL
- F16H—GEARING
- F16H37/00—Combinations of mechanical gearings, not provided for in groups F16H1/00 - F16H35/00
- F16H37/02—Combinations of mechanical gearings, not provided for in groups F16H1/00 - F16H35/00 comprising essentially only toothed or friction gearings
- F16H37/06—Combinations of mechanical gearings, not provided for in groups F16H1/00 - F16H35/00 comprising essentially only toothed or friction gearings with a plurality of driving or driven shafts; with arrangements for dividing torque between two or more intermediate shafts
- F16H37/08—Combinations of mechanical gearings, not provided for in groups F16H1/00 - F16H35/00 comprising essentially only toothed or friction gearings with a plurality of driving or driven shafts; with arrangements for dividing torque between two or more intermediate shafts with differential gearing
- F16H37/0833—Combinations of mechanical gearings, not provided for in groups F16H1/00 - F16H35/00 comprising essentially only toothed or friction gearings with a plurality of driving or driven shafts; with arrangements for dividing torque between two or more intermediate shafts with differential gearing with arrangements for dividing torque between two or more intermediate shafts, i.e. with two or more internal power paths
- F16H37/084—Combinations of mechanical gearings, not provided for in groups F16H1/00 - F16H35/00 comprising essentially only toothed or friction gearings with a plurality of driving or driven shafts; with arrangements for dividing torque between two or more intermediate shafts with differential gearing with arrangements for dividing torque between two or more intermediate shafts, i.e. with two or more internal power paths at least one power path being a continuously variable transmission, i.e. CVT
- F16H2037/088—Power split variators with summing differentials, with the input of the CVT connected or connectable to the input shaft
- F16H2037/0886—Power split variators with summing differentials, with the input of the CVT connected or connectable to the input shaft with switching means, e.g. to change ranges
Definitions
- This invention relates to continuously variable transmission and more particularly to starting devices for toroidal transmissions.
- Toroidal transmissions are either half toroidal or full toroidal traction drives which typically utilize dual cavities for maximum efficiency.
- the dual cavity units have two input discs and two output discs each having a toroidal or partial toroidal shape.
- the output discs are typically located centrally between the input discs.
- Each input disk is engaged with a respective output disc through a plurality of traction rollers. The angle of the rollers is varied to change the drive ratio between the input and output discs.
- the dual cavity continuously variable unit (CVU) requires either a countershaft or a split torque arrangement to transmit power from the center (output) discs.
- Half toroidal CVUs can use an input starting device, however, full toroidal CVU employ a geared neutral arrangement to effect vehicle launch.
- a geared neutral arrangement is shown in U.S. Pat. No. 5,607,372 issued to Lohr on Mar. 4, 1997.
- This patent describes a half toroidal CVU having a coaxial split torque arrangement having a planetary carrier and two sun gear members.
- the carrier is the CVU input member and one of the sun gears is driven by the CVU output member.
- the other sun gear (output) is drivingly connected to a planetary gear assembly.
- CVU continuously variable transmission
- a split torque planetary gear set is combined with a full toroidal CVU to provide a forward variable ratio range and a reverse fixed ratio.
- the CVU has input members directly driven by a prime mover and the planetary gear set has a planet carrier member driven by the prime mover and a sun gear member driven by the output member of the CVU.
- the planetary gear set has two ring gear members that rotate in opposite directions (relative to each other) when the CVU is set at a maximum underdrive ratio.
- a selectively operable mechanical clutch is disposed between the ring gear members and a selectively engageable starting clutch to provide a forward output and a reverse output from the CVU to the starting clutch.
- the ratio of the sun gear member to one ring gear member establishes a first directional output between the prime mover and a transmission output shaft driven by the starting clutch, and the ratio between the sun gear member and the other ring gear member establishes a second directional output, opposite the first directional output, between the prime mover and the transmission output shaft.
- the CVU ratio remains constant during reverse operation and is varied during forward operation.
- the CVU is maintained at a maximum underdrive ratio during reverse operation and varied between the maximum underdrive ratio and a maximum overdrive ratio during forward operation.
- the vehicle speed in forward operation is changed by either or both CVU ratio and prime mover speed, and the vehicle speed in reverse operation is changed by prime mover speed only.
- the starting clutch is engaged to launch the vehicle in both the forward and the reverse directions.
- This invention uses a CVU and a coaxial planetary gear set with a “split torque arrangement”.
- a first ring gear member to sun gear member ratio is selected to provide the desired maximum overdrive ratio in the backwards direction (opposite engine rotation) of the CVU. This will increase the transmission overall ratio to approximately twice the CVU overall ratio, which will greatly improve the ability of the starting clutch to launch the vehicle at maximum underdrive. Selecting a backwards output direction of rotation, for forward drive operation, allows a design with minimum content and higher efficiency than the forward output designs.
- Reverse is achieved by adding a second ring gear member to provide a speed ratio equal in magnitude (with opposite direction) to the lowest forward CVT speed ratio. When the torque is output through the second ring gear member, the transmission could be used as a geared neutral CVT, however, the torque capacity and efficiency will be lower than the path provided by the first ring member.
- the backward transmission output shaft rotation requires a “backwards” hypoid to provide a forward vehicle direction of travel.
- the hypoid gears used on the front axle of today's four wheel drive vehicles are generally designed to produce maximum efficiency with the opposite “prop shaft” rotation. Therefore, placing a “front” hypoid in the rear will provide the correct gear geometry for maximum efficiency with reverse prop shaft rotation; however, the wheel direction of rotation will not be correct.
- the front hypoid will need to be rotated 180 degrees about the prop shaft (i.e. installed upside down) to provide the correct wheel direction of rotation.
- the proposed gear arrangement minimizes spin losses by using a manual transmission type dog clutch (with synchronizers) to eliminate the cost and spin losses of a second starting clutch.
- the synchronizers will only have to accelerate the inertia of the inner clutch plates and hub when shifting between forward and reverse. This inertia is significantly lower than the inertia of the driven disk and input shaft of a conventional manual transmission.
- the synchronizer can be activated by a conventional mechanical mechanism that is attached to the PRNDL lever, not shown, for minimum cost, or it can be activated hydraulically by any of the well-known electro-hydraulic control systems.
- FIG. 1 is a schematic representation of a powertrain having a transmission incorporating the present invention.
- FIG. 2 is a speed ratio plot of a CVT incorporating the present invention.
- a powertrain 10 has a conventional internal combustion engine 12 , a spring vibration damper 14 , a continuously variable transmission (CVT) 16 , and a final drive gearing mechanism 18 .
- the engine 12 is a throttle controlled device that operates within a speed range in a conventional manner.
- the spring damper 14 is a conventional device that effectively eliminates or significantly reduces the torsional impulses of the engine 12 to prevent any noticeable vibrations at an input shaft 42 .
- the final drive gearing mechanism 18 is a conventional gear mechanism.
- the CVT 16 includes a full toroidal continuously variable unit (CVU) 20 , a planetary gear arrangement 22 , a selectively operable mechanical clutch 24 and a selectively engageable fluid operated friction clutch 26 .
- the CVU 16 has two input members 30 and 32 , two output members 34 and 36 , and a plurality of equiangularly spaced traction rollers 38 and 40 .
- the rollers 38 are maintained in rolling contact with toroidal surfaces on the input member 30 and the output member 34 .
- the traction rollers 40 are maintained in rolling contact with the input member 32 and the output member 36 .
- This type of CVU is well-known.
- the angle of the traction rollers relative to the toroidal center of the torus formed by the input member 30 and output member 34 and the torus formed by the input member 32 and the output member 36 determines the drive ratio between the input shaft 42 , connected between the damper 14 and the input members 30 , 32 and a CVU output shaft 44 connected with the output members 34 , 36 .
- the output members 34 , 36 are secured together or otherwise formed integrally.
- the planetary gear set 22 includes a sun gear member 46 , a pair of ring gear members 48 , 50 and a planet carrier assembly member 52 .
- the planet carrier assembly member 52 has a carrier 60 on which is rotatably supported a plurality of pinion gear members 54 , 56 , and 58 .
- the pinion gear members 54 mesh with the sun gear member 46 , the pinion gear members 56 , and the pinion gear members 58 .
- the pinion gear members 56 mesh with the ring gear member 50 and the pinion gear members 58 mesh with the ring gear member 48 .
- the intermeshing pinion gear members 54 , 56 , and 58 are arranged in equiangularly spaced groups of three or four in a well-known manner.
- the carrier 60 is continuously connected for common rotation with the input CVT shaft 42 and the input members 30 and 32 .
- the sun gear member 46 is continuously connected for common rotation with the CVU output shaft 44 .
- the ring gear member 48 is continuously connected for common rotation with a reverse input member 62 of the mechanical clutch 24 and the ring gear member 50 is continuously connected for common rotation with a forward input member 64 of the mechanical clutch 24 .
- the mechanical clutch 24 has a conventional manual transmission type dog clutch and synchronizer assembly 66 that is connected for common rotation with a clutch input member 68 of the friction clutch 26 . As is well-known, the synchronizer assembly will permit the connection of either the reverse input member 62 or the forward input member 64 with the clutch input member 68 .
- the friction clutch 26 includes the input member 68 , a first plurality of friction members 70 , a second plurality of friction members 72 , a hub 74 , an apply piston 76 and a backup plate 78 .
- the friction members 70 are splined to the clutch input member 68 .
- the friction members 72 and the backup plate 78 are splined to the hub 74 .
- the apply piston 76 is slidably disposed in the hub 74 .
- the hub 74 is drivingly connected with a transmission output shaft 80 that is connected with the final drive gearing 18 .
- the piston 76 and the hub 74 cooperate to form an apply chamber 82 which, when pressurized will cause the piston to enforce frictional engagement of the friction members 70 and 72 to establish a drive relation between the clutch input member 68 and the transmission output shaft 80 and therefore between the engine 12 and the final drive gearing 18 .
- the planetary gearing 22 provides both the split torque connection and the speed ratio between the input shaft 42 , the CVU 20 and the output shaft clutch input member 68 .
- the friction clutch 26 provides the starting or launch function for the vehicle, not shown, in which the powertrain 10 is incorporated.
- the carrier 60 and the input members 30 and 32 are driven forwardly (engine output direction) continuously by the engine 12 .
- the sun gear member 46 is driven backwardly (opposite engine direction.
- the ratio of the number of teeth on the ring gear member 48 and the sun gear member 46 is 1.650 and the ratio of the number of teeth on the ring gear member 50 to the sun gear member 48 is 1.214.
- the maximum underdrive speed ratio (output speed/input speed) of the CVU 20 is 0.40 and the maximum overdrive speed ratio is 2.40.
- the ring gear member 50 will rotate opposite the sun gear member 46 to provide a reverse drive ratio at the member 62 at a value of 0.15.
- the ring gear member 20 and the member 64 will rotate opposite the sun gear member 46 in a range of values between 0.15 (underdrive) and 1.80 (overdrive).
- the clutch 26 disengaged, the output shaft 80 will be disconnected from engine power.
- the clutch 26 is engaged in a controlled manner by a conventional clutch engagement system that generally includes either an electronic control or a manual control.
- the ratio of the CVU 20 is controlled by a conventional electronic control that includes a conventional programmable digital computer and a plurality of input signals such as speed, ratio set, ratio desired, throttle setting, and drive condition selected.
- a conventional electronic control that includes a conventional programmable digital computer and a plurality of input signals such as speed, ratio set, ratio desired, throttle setting, and drive condition selected.
- the CVU 20 will be set at the maximum underdrive condition and remain at that setting throughout the entire engine speed range as shown at point 82 of the speed plot in FIG. 2.
- the ratio of the CVU 20 will also be set at the maximum underdrive condition.
- the operator actuates the throttle either the CVU 20 ratio can change or the engine speed can change or both can change.
- the overall ratio of the CVT 16 will operate along the line 84 between the points 86 and 88 as shown in FIG. 2.
- the output of the CVU 20 is controlled along the line 90 between the points 92 and 94 of the speed plot in FIG. 2 and with the present embodiment the input/output ratio varies from ⁇ 0.40 to ⁇ 2.40.
- the mechanical input to the CVU 20 is represented by the vector 96 and has an end point 98 which is unity or +1.0.
- the “Y” axis of the plot represents the speed relationship between the members of the planetary gear set 22
- the “X” axis represents the ratio values of the members of the planetary gear set 22 .
- the point 100 represents the carrier assembly member 52
- the point 102 represents the ring gear member 48
- the point 104 represents the ring gear member 50
- the point 106 represents the sun gear member 46 .
- the distances along the “Y” axis are determined by the tooth ratios of the ring gear members to the sun gear member.
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- Engineering & Computer Science (AREA)
- General Engineering & Computer Science (AREA)
- Mechanical Engineering (AREA)
- Transmission Devices (AREA)
Abstract
Description
- This invention relates to continuously variable transmission and more particularly to starting devices for toroidal transmissions.
- Toroidal transmissions are either half toroidal or full toroidal traction drives which typically utilize dual cavities for maximum efficiency. The dual cavity units have two input discs and two output discs each having a toroidal or partial toroidal shape. The output discs are typically located centrally between the input discs. Each input disk is engaged with a respective output disc through a plurality of traction rollers. The angle of the rollers is varied to change the drive ratio between the input and output discs. The dual cavity continuously variable unit (CVU) requires either a countershaft or a split torque arrangement to transmit power from the center (output) discs.
- Half toroidal CVUs can use an input starting device, however, full toroidal CVU employ a geared neutral arrangement to effect vehicle launch. One example of a geared neutral arrangement is shown in U.S. Pat. No. 5,607,372 issued to Lohr on Mar. 4, 1997. This patent describes a half toroidal CVU having a coaxial split torque arrangement having a planetary carrier and two sun gear members. The carrier is the CVU input member and one of the sun gears is driven by the CVU output member. The other sun gear (output) is drivingly connected to a planetary gear assembly. By changing the roller angle in one direction, from neutral, a forward output is achieved and by changing the roller angle in the other direction, from neutral, a reverse output is achieved. This avoids the need for a starting device.
- It is an object of the present invention to provide an improved continuously variable transmission (CVT) having a full toroidal CVU and an output starting clutch.
- In one aspect of the present invention, a split torque planetary gear set is combined with a full toroidal CVU to provide a forward variable ratio range and a reverse fixed ratio. In another aspect of the present invention, the CVU has input members directly driven by a prime mover and the planetary gear set has a planet carrier member driven by the prime mover and a sun gear member driven by the output member of the CVU. In another aspect of the present invention, the planetary gear set has two ring gear members that rotate in opposite directions (relative to each other) when the CVU is set at a maximum underdrive ratio.
- In yet another aspect of the present invention, a selectively operable mechanical clutch is disposed between the ring gear members and a selectively engageable starting clutch to provide a forward output and a reverse output from the CVU to the starting clutch. In still another aspect of the present invention, the ratio of the sun gear member to one ring gear member establishes a first directional output between the prime mover and a transmission output shaft driven by the starting clutch, and the ratio between the sun gear member and the other ring gear member establishes a second directional output, opposite the first directional output, between the prime mover and the transmission output shaft.
- In a further aspect of the present invention, the CVU ratio remains constant during reverse operation and is varied during forward operation. In a yet further aspect of the present invention, the CVU is maintained at a maximum underdrive ratio during reverse operation and varied between the maximum underdrive ratio and a maximum overdrive ratio during forward operation. In a still further aspect of the present invention, the vehicle speed in forward operation is changed by either or both CVU ratio and prime mover speed, and the vehicle speed in reverse operation is changed by prime mover speed only. In a yet still further aspect of the present invention, the starting clutch is engaged to launch the vehicle in both the forward and the reverse directions.
- This invention uses a CVU and a coaxial planetary gear set with a “split torque arrangement”. A first ring gear member to sun gear member ratio is selected to provide the desired maximum overdrive ratio in the backwards direction (opposite engine rotation) of the CVU. This will increase the transmission overall ratio to approximately twice the CVU overall ratio, which will greatly improve the ability of the starting clutch to launch the vehicle at maximum underdrive. Selecting a backwards output direction of rotation, for forward drive operation, allows a design with minimum content and higher efficiency than the forward output designs. Reverse is achieved by adding a second ring gear member to provide a speed ratio equal in magnitude (with opposite direction) to the lowest forward CVT speed ratio. When the torque is output through the second ring gear member, the transmission could be used as a geared neutral CVT, however, the torque capacity and efficiency will be lower than the path provided by the first ring member.
- The backward transmission output shaft rotation requires a “backwards” hypoid to provide a forward vehicle direction of travel. The hypoid gears used on the front axle of today's four wheel drive vehicles are generally designed to produce maximum efficiency with the opposite “prop shaft” rotation. Therefore, placing a “front” hypoid in the rear will provide the correct gear geometry for maximum efficiency with reverse prop shaft rotation; however, the wheel direction of rotation will not be correct. The front hypoid will need to be rotated 180 degrees about the prop shaft (i.e. installed upside down) to provide the correct wheel direction of rotation.
- The proposed gear arrangement minimizes spin losses by using a manual transmission type dog clutch (with synchronizers) to eliminate the cost and spin losses of a second starting clutch. The synchronizers will only have to accelerate the inertia of the inner clutch plates and hub when shifting between forward and reverse. This inertia is significantly lower than the inertia of the driven disk and input shaft of a conventional manual transmission. The synchronizer can be activated by a conventional mechanical mechanism that is attached to the PRNDL lever, not shown, for minimum cost, or it can be activated hydraulically by any of the well-known electro-hydraulic control systems.
- FIG. 1 is a schematic representation of a powertrain having a transmission incorporating the present invention.
- FIG. 2 is a speed ratio plot of a CVT incorporating the present invention.
- A
powertrain 10 has a conventionalinternal combustion engine 12, aspring vibration damper 14, a continuously variable transmission (CVT) 16, and a finaldrive gearing mechanism 18. Theengine 12 is a throttle controlled device that operates within a speed range in a conventional manner. Thespring damper 14 is a conventional device that effectively eliminates or significantly reduces the torsional impulses of theengine 12 to prevent any noticeable vibrations at aninput shaft 42. The finaldrive gearing mechanism 18 is a conventional gear mechanism. The CVT 16 includes a full toroidal continuously variable unit (CVU) 20, aplanetary gear arrangement 22, a selectively operablemechanical clutch 24 and a selectively engageable fluid operatedfriction clutch 26. - The CVU16 has two
input members output members traction rollers rollers 38 are maintained in rolling contact with toroidal surfaces on theinput member 30 and theoutput member 34. Thetraction rollers 40 are maintained in rolling contact with theinput member 32 and theoutput member 36. This type of CVU is well-known. The angle of the traction rollers relative to the toroidal center of the torus formed by theinput member 30 andoutput member 34 and the torus formed by theinput member 32 and theoutput member 36 determines the drive ratio between theinput shaft 42, connected between thedamper 14 and theinput members CVU output shaft 44 connected with theoutput members output members - The
planetary gear set 22 includes asun gear member 46, a pair ofring gear members carrier assembly member 52. The planetcarrier assembly member 52 has acarrier 60 on which is rotatably supported a plurality ofpinion gear members pinion gear members 54 mesh with thesun gear member 46, thepinion gear members 56, and thepinion gear members 58. Thepinion gear members 56 mesh with thering gear member 50 and thepinion gear members 58 mesh with thering gear member 48. The intermeshingpinion gear members - The
carrier 60 is continuously connected for common rotation with theinput CVT shaft 42 and theinput members sun gear member 46 is continuously connected for common rotation with theCVU output shaft 44. Thering gear member 48 is continuously connected for common rotation with areverse input member 62 of themechanical clutch 24 and thering gear member 50 is continuously connected for common rotation with aforward input member 64 of themechanical clutch 24. Themechanical clutch 24 has a conventional manual transmission type dog clutch andsynchronizer assembly 66 that is connected for common rotation with aclutch input member 68 of thefriction clutch 26. As is well-known, the synchronizer assembly will permit the connection of either thereverse input member 62 or theforward input member 64 with theclutch input member 68. - The
friction clutch 26 includes theinput member 68, a first plurality offriction members 70, a second plurality offriction members 72, ahub 74, an applypiston 76 and abackup plate 78. Thefriction members 70 are splined to theclutch input member 68. Thefriction members 72 and thebackup plate 78 are splined to thehub 74. The applypiston 76 is slidably disposed in thehub 74. Thehub 74 is drivingly connected with atransmission output shaft 80 that is connected with the final drive gearing 18. Thepiston 76 and thehub 74 cooperate to form an applychamber 82 which, when pressurized will cause the piston to enforce frictional engagement of thefriction members clutch input member 68 and thetransmission output shaft 80 and therefore between theengine 12 and the final drive gearing 18. Theplanetary gearing 22 provides both the split torque connection and the speed ratio between theinput shaft 42, theCVU 20 and the output shaftclutch input member 68. Thefriction clutch 26 provides the starting or launch function for the vehicle, not shown, in which thepowertrain 10 is incorporated. - During operation, the
carrier 60 and theinput members engine 12. Thesun gear member 46 is driven backwardly (opposite engine direction. For example, the ratio of the number of teeth on thering gear member 48 and thesun gear member 46 is 1.650 and the ratio of the number of teeth on thering gear member 50 to thesun gear member 48 is 1.214. The maximum underdrive speed ratio (output speed/input speed) of theCVU 20 is 0.40 and the maximum overdrive speed ratio is 2.40. At the maximum underdrive setting, thering gear member 50 will rotate opposite thesun gear member 46 to provide a reverse drive ratio at themember 62 at a value of 0.15. Throughout the ratio spectrum of theCVU 20, thering gear member 20 and themember 64 will rotate opposite thesun gear member 46 in a range of values between 0.15 (underdrive) and 1.80 (overdrive). With the clutch 26 disengaged, theoutput shaft 80 will be disconnected from engine power. To launch the vehicle in either forward or reverse, the clutch 26 is engaged in a controlled manner by a conventional clutch engagement system that generally includes either an electronic control or a manual control. - The ratio of the
CVU 20 is controlled by a conventional electronic control that includes a conventional programmable digital computer and a plurality of input signals such as speed, ratio set, ratio desired, throttle setting, and drive condition selected. When the reverse drive is selected by the operator, theCVU 20 will be set at the maximum underdrive condition and remain at that setting throughout the entire engine speed range as shown atpoint 82 of the speed plot in FIG. 2. When the operator selects the forward drive condition, the ratio of theCVU 20 will also be set at the maximum underdrive condition. However, when the operator actuates the throttle, either theCVU 20 ratio can change or the engine speed can change or both can change. The overall ratio of theCVT 16 will operate along theline 84 between thepoints CVU 20 is controlled along theline 90 between thepoints CVU 20 is represented by thevector 96 and has anend point 98 which is unity or +1.0. The “Y” axis of the plot represents the speed relationship between the members of the planetary gear set 22, and the “X” axis represents the ratio values of the members of the planetary gear set 22. Thepoint 100 represents thecarrier assembly member 52, thepoint 102 represents thering gear member 48, thepoint 104 represents thering gear member 50, and thepoint 106 represents thesun gear member 46. The distances along the “Y” axis are determined by the tooth ratios of the ring gear members to the sun gear member.
Claims (2)
Priority Applications (2)
Application Number | Priority Date | Filing Date | Title |
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US09/764,233 US6422966B1 (en) | 2001-01-19 | 2001-01-19 | Toroidal transmission with a starting clutch |
DE10201687A DE10201687B4 (en) | 2001-01-19 | 2002-01-17 | Toroidal transmission with start-up clutch |
Applications Claiming Priority (1)
Application Number | Priority Date | Filing Date | Title |
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US09/764,233 US6422966B1 (en) | 2001-01-19 | 2001-01-19 | Toroidal transmission with a starting clutch |
Publications (2)
Publication Number | Publication Date |
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US6422966B1 US6422966B1 (en) | 2002-07-23 |
US20020098936A1 true US20020098936A1 (en) | 2002-07-25 |
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Application Number | Title | Priority Date | Filing Date |
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US09/764,233 Expired - Lifetime US6422966B1 (en) | 2001-01-19 | 2001-01-19 | Toroidal transmission with a starting clutch |
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US (1) | US6422966B1 (en) |
DE (1) | DE10201687B4 (en) |
Cited By (3)
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US8617020B2 (en) | 2007-02-21 | 2013-12-31 | Torotrak (Development) Limited | Continuously variable transmission |
US20140045637A1 (en) * | 2011-04-29 | 2014-02-13 | Transmission Cvtcorp Inc. | Drivetrain provided with a cvt |
EP2969631B1 (en) * | 2013-03-15 | 2019-05-22 | Allison Transmission, Inc. | Variator bypass clutch |
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DE10021912A1 (en) * | 2000-05-05 | 2001-11-08 | Daimler Chrysler Ag | Drive train for motor vehicle has second planet wheel with diameter such that for stepping up of variable speed gear contact point of second planet wheel with driven element corresponds to center of rotation of second planet wheel |
JP4151300B2 (en) * | 2002-04-12 | 2008-09-17 | 日本精工株式会社 | Continuously variable transmission |
DE10249487A1 (en) * | 2002-10-24 | 2004-05-06 | Zf Friedrichshafen Ag | Power split transmission |
JP4281370B2 (en) * | 2003-02-10 | 2009-06-17 | 日本精工株式会社 | Continuously variable transmission |
US7048667B2 (en) * | 2004-02-09 | 2006-05-23 | Ford Global Technologies, Llc | Power split transaxle for producing stepless reverse, forward and geared neutral speed ratios |
US10036456B2 (en) * | 2013-11-29 | 2018-07-31 | Transmission Cvtcorp Inc. | Drive assembly provided with a continuously variable transmission and a direction reversing mechanism |
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JPS5666544A (en) * | 1979-11-05 | 1981-06-05 | Toyota Motor Corp | Speed change gear for vehicle |
US4539866A (en) * | 1983-11-03 | 1985-09-10 | General Motors Corporation | Continuously variable transmission |
GB9026830D0 (en) * | 1990-12-11 | 1991-01-30 | Fellows Thomas G | Improvements in or relating to continuously-variable-ratio transmissions of toroidal-race rolling-traction type |
US5607372A (en) * | 1995-01-13 | 1997-03-04 | The Torax Company, Inc. | Co-axial drive for a toroidal drive type transmission |
US5989146A (en) * | 1997-03-21 | 1999-11-23 | New Venture Gear, Inc. | On-demand four-wheel drive transmission |
US5803858A (en) * | 1997-05-23 | 1998-09-08 | General Motors Corporation | Powertrain transmission with torque converter planetary gearing and a continuously variable transmission unit |
US6099431A (en) * | 1999-05-06 | 2000-08-08 | Ford Global Technologies, Inc. | Method for operating a traction drive automatic transmission for automotive vehicles |
US6056661A (en) * | 1999-06-14 | 2000-05-02 | General Motors Corporation | Multi-range transmission with input split planetary gear set and continuously variable transmission unit |
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2001
- 2001-01-19 US US09/764,233 patent/US6422966B1/en not_active Expired - Lifetime
-
2002
- 2002-01-17 DE DE10201687A patent/DE10201687B4/en not_active Expired - Fee Related
Cited By (3)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US8617020B2 (en) | 2007-02-21 | 2013-12-31 | Torotrak (Development) Limited | Continuously variable transmission |
US20140045637A1 (en) * | 2011-04-29 | 2014-02-13 | Transmission Cvtcorp Inc. | Drivetrain provided with a cvt |
EP2969631B1 (en) * | 2013-03-15 | 2019-05-22 | Allison Transmission, Inc. | Variator bypass clutch |
Also Published As
Publication number | Publication date |
---|---|
US6422966B1 (en) | 2002-07-23 |
DE10201687A1 (en) | 2002-08-29 |
DE10201687B4 (en) | 2009-12-31 |
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